232 



The Classification of Lower Organisms 



Fig. 44. — Infusoria, order Hypotricha: a, Aspidisca x 800. b, Stylonychia 

 X 400. C, Euplotes x 400. d-n, Euplotes Patella after Turner (1930); d-h, stages 

 of mitosis x 2,000, i, conjugating cells x 400; j, k, polar and equatorial views of the 

 heterotypic division in a conjugant x 2,000; 1, early anaphase of the homeotypic 

 division x 2,000; m, first division of the zygote nucleus x 2,000; n, a cell after con- 

 jugation X 400, the macronucleus breaking up, the zygote nucleus divided into four, 

 of which one is to become a macronucleus, one a micronucleus, and two are to 

 undergo dissolution. 



